This invention relates in general to engine shrouds for gas turbine engines and, more specifically, to an improved integral duct for those shrouds.
Ducted fan jet engines for aircraft applications have come into widespread use. Such engines include a core engine within a streamlined shroud, a stage of fan blades mounted upstream of the engine and driven thereby, and a nacelle surrounding the fan blades and shroud and spaced from the shroud to provide a bypass duct between nacelle and shroud through which compressed air is forced by the fan blades.
The shroud which surrounds the engine and forms both the housing for the engine and the interior wall of the bypass duct is often formed from two halves which are fastened together to form the shroud. This arrangement facilitates engine servicing, removal and reinstallation. Each shroud half consists of a center section having a "C" shaped transverse cross-section which forms half of the tubular shroud around the engine and two radially extending bifurcations (flanges) attached to the edges of the "C" sections to aid in supporting the shroud within the engine casing and nacelle and to carry means for securing the shroud halves together.
Ordinarily, the "C" sections and the bifurcations, are separately constructed honeycomb panels, mechanically joined by means of metallic corner angles or other clamping and fastening arrangements.
While these prior corner fastening methods have been effective, they are cumbersome, heavy, require considerable skill to install and are more expensive and less reliable than a continuous integral panel would be. Thus, there is a continuing need by for shrouds formed as a continuous panel, eliminating corner fittings and mechanical fasteners.